
MAINTENANCE MANUAL OF ENGINE
71
4. Assembling the cooling part
4.1 Installing the water pump assembly
Clean the surface of cylinder liner and cooling liq-
uid and lubricating oil passage; water jacket can be
cleaned by special solvent, which shall follow the
instruction of manufacture when using.
The basic assembly sequence and disassembly se-
quence for water pump as shall be opposite. How-
ever, except replacing bushing and seal ring, parts
that have been cleaned shall be first checked and
measured. If the wear has exceeded the limit, re-
place the new ones. It can be assembled only after
all parts are qualified.
◆
Fit clearance between water pump shaft and
bearing shall be (0.010-0.012)mm.
It is allowed to be (0.010~ 0.030) mm for overhaul.
◆
Fit of water pump bearing and bearing hole: it is
generally (0.02- 0.02) mm; it is allowed to be
(0.02-0.044) mm for overhaul.
◆
After installation, water pump impeller shall be
generally (0.1-0.5)mm higher than pump shaft.
◆
After water pump is installed, the clearance be-
tween impeller outer edge and pump case inner cav-
ity is generally 1mm; there shall be (0.075-1)mm
clearance between impeller and pump cover.
◆
All bolts and nuts shall be tightened by specified
torque and locking shall be reliable.
◆
Drain hole below water pump shall be smooth.
◆
After installation of water pump, lubricating
grease with specified mark shall be refueled to wa-
ter pump bearing.
◆
When installing, pay special attention to the axial
clearance between water pump impeller and water
pump housing, clearance between water pump im-
peller and radial seal of housing. Pay attention to
the lubricating conditions of bearing.
A-Water pump housing
B-Nut
C-Gasket
D-Water pump connecting shaft bearing
E-Water seal
F-Water pump impeller
A
B
C
D
E
F